1. Field of the Invention
The present invention relates to a reticle-carrying container for storing a reticle, during transportation, used for a light exposure apparatus or the like that transfers a set pattern to a substrate.
2. Description of the Background Art
Semiconductor devices and liquid crystal display devices are manufactured in the process of photolithography. In this process, an image of a pattern formed on a reticle (including a photo mask) is projected and transferred by a light exposure apparatus onto a substrate such as a semiconductor wafer and glass plate. At that time, the projected pattern reacts with a photosensitive agent applied on the substrate, and then a circuit is formed through the subsequent operations.
During this process, a reticle is handled by storing in a dedicated reticle-carrying container in order to prevent contamination with dust, etc. and damage from contact with other components.
For making an intricate circuit, it is necessary to provide a large number of circuit patterns on the substrate. Accordingly, many reticles are prepared and many patterns are exposed in layers on the substrate.
FIG. 2 shows one example of an apparatus used in the photolithography process. In the figure, numeral 1 indicates a light exposure apparatus that projects and transfers a circuit pattern onto the substrate. A numeral 2 denotes a reticle stocker in which a large number of reticles are stored and retained. A numeral 3 indicates a reticle-carrying container which stores reticles. A numeral 4 indicates a transfer rail provided between a light exposure apparatus 1 and a reticle stocker 2, which transfers the reticles stored in a reticle-carrying container 3 between these two components. A numeral 5 indicates a transfer mechanism provided on the transfer rail 4, which holds and transfers directly the reticle-carrying container 3.
These components are controlled by a controller (not shown). With this, the reticles required for a circuit pattern stored in the reticle-carrying container 3 are transferred by the transfer mechanism 5 on the transfer rail 4 from the reticle stocker 2 to the light exposure apparatus 1. The reticles no longer required in the light exposure apparatus 1 are returned to the reticle stocker 2 by the transfer mechanism 5 on the transfer rail 4.
If the reticles used in the above described process are contaminated with dust, etc. or damaged by contact with other components, it is impossible to form an accurate circuit pattern. Therefore, for supporting the reticles safely and securely, the reticles are stored in the reticle-carrying containers 3.
One example of the reticle-carrying container 3 is shown in Japanese Patent Laid-Open No. 10-163094. The reticle supporting means set forth in Japanese Patent Laid-Open No. 10-163094 is a pin. As means for supporting a reticle from underneath, the reticle supporting pins are provided on the four corners of the reticle. In addition, as means for supporting a reticle from its periphery so as not to be shifted in a horizontal direction, the stopper pins for preventing a horizontal movement are provided. Moreover, as means for supporting a reticle from above, a reticle retainer is provided. These means support and fix the reticle in X, Y and Z directions.
In general, kinematic pin grooves are provided on the underside of the reticle-carrying container and are engaged with the kinematic pins of a light exposure apparatus, which allows the reticle-carrying container to be positioned with accuracy. These kinematic pin grooves and kinematic pins are arranged in a set of three, one each at the apexes of an approximately isosceles triangle.
However, if the above mentioned conventional reticle-carrying container 3 is turned 180-degrees by mistake in the reticle stocker 2, the kinematic pins and the kinematic pin grooves are opposed and are not properly mated with one another, and thus the reticle-carrying container 3 cannot be fastened. Accordingly, much attention to the orientation of the reticle-carrying container 3 is required, which leads to impairment of working efficiency.